OpenDose3D: A Free, Open-Source Clinical Dosimetry Software for Patient-Specific Dosimetry

Software tools for nuclear medicine dosimetry are becoming available. Yet, it is difficult to compare clinical dosimetry workflows implemented in academic or commercial software tools, and this limits the emergence of a standardized clinical dosimetry practice. This article introduces OpenDose3D (OD3D), an open-source software designed to provide image-based, patient-specific dosimetry in nuclear medicine. OD3D implements multiple clinical dosimetry workflows and exports intermediate results, enabling comparison between various dosimetry approaches. <b>Methods:</b> OD3D was developed as an extension of the 3D Slicer platform that already presents several components adapted to nuclear medicine imaging. Three additional modules were created: a calibration module for deriving sensitivity factors and recovery coefficients for partial-volume effect correction, a module for calculating absorbed dose rate images based on 3 algorithms, and a module for fitting and integrating time-dependent variables (activity or absorbed dose rates). The software was tested against phantom data from the MRTDosimetry project and image data from the 2021 SNMMI Dosimetry Challenge dataset. <b>Results:</b> The phantom-based validation process showed excellent agreement (deviations <3%) with the reference values for calibration and organ dosimetry. For the tumor compartment, the difference in absorbed doses was attributed to pharmacokinetic modeling. The OD3D results using data from the SNMMI Dosimetry Challenge (patient A) were consistently close to the reported values for the 3 proposed tasks: absolute <i>z</i> score was less than 1. <b>Conclusion:</b> The OpenDose collaboration provides free dosimetry tools and data to the community. The OD3D software is a research tool that can be used for clinical dosimetry, to educate professionals, and to benchmark available academic or commercial clinical dosimetry software tools.